Evaluation of Depositional Mechanisms in Sediment-Hosted Micron Gold Deposits

9523771 Kesler本提案要求支持对可能在沉积物中的微米金矿床中沉积存款金的工艺进行评价。 尽管它们很重要，但我们缺乏这些矿石中金沉积的综合模型，主要是因为我们不了解矿石中金的矿物学形式及其与地质特征的关系。 为了评价固溶/吸附/电化学沉积法在SHMG矿床中的可行性，我们需要了解：1）不同结构和含金量的黄铁矿的地质背景; 2）黄铁矿上的增生程度可以对比; 3）黄铁矿中金的形态。 回答这些问题的努力将集中在矿床规模的研究在大型双溪存款在内华达州，其中包含广泛的黄铁矿纹理的类型在这里描述。 工作还将包括对北方内华达州古生代沉积岩中黄铁矿的分布进行普查，以测试预先存在的黄铁矿对金沉积的重要性。 除了它们对成因理论的明显重要性之外，这些结果还可以通过在钻探的早期阶段预测等级和划定目标来帮助勘探。

9523771 Kesler This proposal requests support for an evaluation of processes that could deposit gold in sediment-hosted micron gold (SHMG) deposits. Despite their importance, we lack comprehensive models for gold deposition in these ores, largely because we do not understand the mineralogical form of gold in the ore and its relation to geologic features. In order to evaluate the feasibility of the solid solution/adsorbtion/electrochemical depositional processes for SHMG deposits, we need to know: 1) the geologic setting of pyrite with different textures and gold contents; 2) the degree to which overgrowths on pyrite can be correlated; 3) the form of gold in pyrite. Efforts to answer these questions will focus on deposit-scale studies at the large Twin Creeks deposit in Nevada, which contains widespread pyrite textures of the type described here. Work will also include a reconnaissance survey of the distribution of pyrite in Paleozoic sedimentary rocks of northern Nevada to test the importance of pre-existing pyrite to gold deposition. In addition to their obvious importance to genetic theories, results could aid exploration by forecasting grades and delimiting targets during early stages of drilling.